Space Shuttle Discovery Returns to Earth Safely

The wheels on Space shuttle Discovery kick up dust on Runway 33 as they touch down at NASA's Kennedy Space Center, concluding the 15-day mission STS-120 to the International Space Station on Nov. 7, 2007.Credit: NASA/George Shelton.

CAPE
CANAVERAL, Fla. - Space shuttle Discovery and its seven-astronaut crew returned
safely to Earth today, sailing over the heartland of America after a busy
construction flight to the International Space Station (ISS).

The 100-ton
spaceship touched down on the tarmac at 1:01 p.m. EST (1801 GMT) here at the Kennedy Space Center's Shuttle Landing Facility, shortly after unleashing two
chest-thumping sonic booms.

"Well
hello there! It's nice to be back in Florida," shuttle commander Pamela
Melroy said as she piloted Discovery to a safe landing. The Rochester, N.Y.-native
made history during her mission as one of two female commanders in space at the
same time, sharing the limelight with ISS Expedition 16 commander Peggy
Whitson.

Melroy and
her STS-120
mission crew hauled a bus-sized room to the space station, relocated one of
its 17.5-ton solar power plants, repaired a torn solar blanket and replaced
flight engineer Clay Anderson with mission specialist Dan Tani.

Anderson spent about five months aboard the
ISS, and said that his homecoming is going to be a bittersweet affair.

"They
say all great things have to come to an end, and I'm really sorry I have to
agree with that for now," Anderson told mission controllers yesterday.
"But I had an awesome ride with several awesome crews and I'm very excited
to come on home."

Discovery
racked up 6.2 million miles (10 million kilometers) during its 16-day journey
that began on Oct. 23. The spaceship orbited the Earth 238 times, most of which
while docked at the ISS for about 11 days.

Returning
to Earth with Melroy and Anderson were shuttle pilot George Zamka and mission
specialists Scott Parazynski, Stephanie Wilson, Doug Wheelock and Italian
astronaut Paolo Nespoli of the European Space Agency.

"What
we demonstrated this flight, I think, is the real value of having humans in
space," said Wayne Hale, NASA's space shuttle program manager. Hale went
so far as to call the effort "one of most complex EVA repairs in the
history of the agency."

The
unprecedented repair job sent Parazynski, a veteran spacewalker, to a far end
of the space station, dangling on the end of a shaky robotic arm. While
Wheelock looked on, Parazynski stitched up tears in the component with
"cuff links" made by astronauts on board the ISS.

Melroy said
she was more than a little concerned about Parazynski's close approach to the
electrified blanket.

"You
may have heard me … kind of squeak out 'be careful!' as I saw the solar
array coming towards him," Melroy said. As Parazynski went to work,
however, the commander explained she became comfortable with the risky
operation.

Yet before
Discovery's crew mended the damaged solar wing, they attached the Italian-made Harmony
module to the space station. The nearly 16-ton room added more than 2,500
cubic feet (71 cubic meters) of space to the orbital laboratory and will serve
as a vital hub for future expansion.

Astronauts
also relocated a 35,000-pound (15,875-kilogram) component known as the Port 6
(P6) truss from atop the space station to a permanent home on the end of the
ISS.

Yet even as
NASA celebrates the Discovery and its crew's success, a
busy month awaits the three-person Expedition 16 crew still in space.

Crunch
time

Space
shuttle Atlantis is set to ferry another massive room called Columbus to the
station next month, but spaceflyers Whitson, Tani and cosmonaut Yuri
Malenchenko will need to relocate and outfit Harmony before the arrival of the
European laboratory.

Two other
immense payloads are also set to arrive at the space station by May 2008.
Further adding to mission managers' concerns is a grit-covered
gear that rotates the station's starboard solar wings to help maximize
power output. Without enough power, the space station may not be able to
support future laboratory modules.

Pete
Hasbrook, increment manager for Expedition 16, said fixing the
solar-array-orienting device is quickly becoming a major priority for the
agency, as it has international partners to appease. Any repair efforts would
likely occur after the December shuttle flight, he added.

"We
still … don't know the source of this debris, the grit," said
Hasbrook. "There's a lot of discussion about what's our best bang for the
buck," he said of several cleanup ideas in the works.

Until the
device is restored, space station program manager Mike Suffredini said the
device will only be moved occasionally, cutting into the orbital laboratory's
overall power output. But the exact impact of the device to ISS power
management is still being reviewed, he added.

Today's
successful landing ended Discovery's 34th spaceflight, which is the 23rd
shuttle mission to the space station and the 120th orbiter flight in NASA
history. It also marked NASA's third of four shuttle flights planned for this
year.

If the
space agency can squeeze in the launch of Atlantis in December, followed closely
by STS-123 in February 2008, Discovery will return to the launch pad again in
late April 2008.

But as for
her crew's eventful mission, Melroy said before her flight that she considers
it every astronaut's dream.

"It
has been a dream, it really [has]," she told SPACE.com from
Discovery's flight deck yesterday. "But it always is when you go to
space."

NASA
plans to launch at least 10 more shuttle flights to the ISS - with the possibility
of two more - to complete construction of the orbital laboratory by September
2010, when the agency is set to retire its three-orbiter fleet. A
non-space-station construction flight to upgrade the Hubble Space Telescope is
slated to fly next year.

NASA is
broadcasting Discovery's STS-120 mission live on NASA TV. Click here for mission updates and
NASA TV from SPACE.com.

Staff
writer Tariq Malik contributed to this report from New York City.